Gyms scare me. There is nothing in the world that reduces me more quickly to an undersized, frizzy-haired 12-year-old than stepping into a new gym where everyone else knows the complicated setups, the locations of the lockers, how to sign up for spinning classes, and what to bring to class.

Not that I want to do any of these things, mind you. I like to walk, and I like to ride my bicycle, the Vista Sophisticate, in the most dilatory fashion. I join gyms, the very few times I have, purely for step aerobics, the one form of organized exercise I can tolerate. But when forced to endure variations - involving weights and circuits and equipment - I am invariably the one without her own mat, who didn't bring a towel, or who doesn't know what the resistance band is for. And I only do step aerobics because various medical professionals are always telling me exercise will benefit my migraines and my depression and the other things that are wrong with my brain.

The only time I found belonging to a gym remotely congenial (which is to say, I went more than once) is the one I joined in Paris at a student rate. It was one of the first "American-style" gyms - indeed, they'd imported a bunch of hard-bodied, enthusiastic instructors from the States - but the attitude of the gym-goers was very French indeed. No one dressed in appropriate workout clothes, with the possible exception of the purple-haired old woman who, preparatory to kick-boxing, wrapped her hands like a boxer. Half the class would leave midway through for a cigarette; others would simply stop when it became unpleasant and stand on the sidelines, looking baffled and irritated. That was about my speed.

I hadn't belonged to anything since never going to the Greenpoint Y two years ago, but the other day, in a fit of self-improvement, I picked up a flyer from a newish spot in an unfamiliar neighborhood and resolved to make myself go before I changed my mind. I signed up for a three-class deal and scheduled a spot in some kind of total-burn-circuit-leaping workout that was taking place the very next day.

My trepidation began, as it invariably does, when I surveyed my exercise wardrobe, which is highly unconvincing and makes me look, at best, like a college modern-dancer, even though I wasn't one. Still, I donned my red sneakers, my cut-off yoga pants, my fairly crummy sports bra and an old Grossinger's t-shirt, packed a change and a water bottle into a "Barney Greengrass: The Sturgeon King" tote, and was on my way.

My heart was hammering as I pushed open the door and was confronted with an efficient receptionist, one of those healthy mini-snack bars full of powerful waters, and the sound of people being efficient on complex machines. Pre-paid pre-paid pre-paid rang in my ears. I tried to feign jaunty confidence as the receptionist pointed me towards a locker. I deposited my tote and made for the bathroom. I pushed open the door.

"IN HERE!" shouted someone. I noticed the "please knock" sign. I was badly shaken, and had to pee, but I didn't want to be standing outside and be recognizable as the intruder when the pee-er came out. I made towards the room where my class was taking place and stopped dead in the doorway. Oh no. About five - only five - beautiful, fit people of both sexes in real exercise gear, the kind from Lulu Lemon or Stella McCartney for Adidas - or what I imagine that stuff looks like - were assembled. One was stretching. Two were bantering with the equally intimidating instructor. They all turned to look at me. My vision darkened. I swayed. I wasn't a mature, confident woman who can laugh at herself and interact with anyone I went to high school with on the subway. No, I was a terrified animal, a creature of instinct caught in a predator's gaze. A wave of pure, unreasoning panic washed over me, and, without thought, I turned and ran. I grabbed my tote from the locker with a slamming of doors and sprinted out the door and down the stairs, muttering "Gotta leave," in the general direction of the startled receptionist.

Once outside, I breathed hard as relief washed over me. Then came the shame. A combination of self-disgust and dismay at the ten - no, 30, since going back was out of the question - bucks I'd swallowed washed over me. I'd had this happen before, once in a Spinning class and once at a highly intimidating Turkish bathhouse where no one spoke English and I hadn't realized I needed to bring my own robe and that it would be full of leering old men in towels. But mostly I knew this feeling from being in Middle School, and feeling like the whole world was that gym.

I walked over the Brooklyn Bridge instead. I resolved to not tell anyone about my shame and instead told everyone immediately in a fit of self-excoriation. I gave my remaining classes to a fit friend and have been eyeing the grimy Curves in my neighborhood. I guess I need to face my demons and try again - but Xanax and working out, I'm guessing, don't go together (despite a storied L.A. history) and I don't see how this is happening otherwise.